System of electric-motor control



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Mal-h 9, 1926.'

H. c. HAsTlNGs Er AL SYSTEM 0F ELECTRIC MOTOR CONTROL Filed oct. 11.1924 2 sheets-sheet 2 Inventors 1 Hammond C. Hastings,

Edward B. Tuppen by M Their Attorney.

fore the main controller vwill vadvance to the i `parallel.positionsfVAlso iingerV 1 `must be energized *byV the 'relay F before the main,controller will advance tothe tapped Yfield position.

The contactgsegment Jislused inconjunction withVv interlocking contacts'on line breaker D to prevent the line breakers Dvand Y `E being closedunless the main controller is inthe-offposition.` A contact segment K,

" lalsoonthe maincontroller, is' used in con'- junctioncwithgitheinterlocking contactsuon line breakerfE and the relay Uk to'provide vmeans for energizingthe pilot motor'N in order that themain ycontrollershall be returned y. to the oit-'position whenV the'master controller isin theg-ofl-position. y

V*Chanical friction brake L is adapted'to bring The methe. pilotmotorlto rest' in ,theV full-on position andalso when returningto theoff posi'-v J tion, asunderthese conditions the pilot Ino- Y torcircuit..=is`opened and it therefore cannot be stoppedv dynamically; The'pilot motor N for operating the main controller is connected'tothebrake Li. and may'beprovided with a shunting resistance 70 inparallelwithvthe armature or aresistance 75 in series .withl thearmature, orboth may be employed. represents an overload relayhavingtwo.. main windings Oa; and Ob connected in the main ,rnotor circuits.-It Yhas Va coil 57 -for setting vthe relay after it has been tripped.by an overload, and is vsetfby closing the control l switch 58 Vto theright,rthus energizing wire 7.' Tl1elundervoltage relay P kisfprovidedas is 'customary, and the reverser R isprovided lwith the'usual'interlocking 'contacts to prevent it being thrown* except when the linebreakers D and E are `inthe open position.v

A braking relayfS isbiased so that its contacts arecl'osedl when thecoil is, deenergized. The relay Tis'provided for energizing` the pilotmotoraccording tothe relative position ofthe interlocks on the linebreakers D,

E, and contacts K,' andthe' contacts of relay f U. ,-Therelay U is;arrangedV to'energize' the pilot motor-and `cause Yit to return'the maincontroller tothe oit-position whenithje inas- 5o; terrcontrollerisin theofl'fposition. ,The

interlock7 maybe arrangedA to Vbe opened wheneitherfmotor or pair of,motors is cut Y outgbyqva suitable `cutout switch; notsliown,

vin order to prevent Vfinger-3 beinggenergized and thus prevent the maincontroller on any particular coachV Ywherea- -vjmotor or motors are cutout2 fromadv'ancing vto the parallel positions. vA contact YV onY themain controller prevents the potential relay-P closing G(')funl'e'ss theV,main controller is in the oft' position. x It will be seen! that-theoff-position of the'main'controller also correspondsVV to the Vfirstposition, depending upon-the position f of the master controller bywhich Athe line breakers are'controlled.

In operation, assuming that no circuits' are i energized'` except they.main collecting! shoes, the main switch (not shown) is closed andthepotential relay' P energized,the current-passing from the positiveshoethrough v the resistance rlgthe coilto y) and through l'the-contactY to earth. The relay P wouldf j not have closed ifthecontrol cylinder had* not -been in the of-positioinas the resistancef- 'r shown would not allow suiiioient current to TheV switch 58 is `nowmovedtothe i right-hand contact, energizingA wire7 andvr thussetting theoverload relay O througln coil 57 to wire 10. `Switch 58fisnow closed tothe left-hand contact, thus energizingif- Y'through contacts 59theterminal 15+' on the.` master controller M. The reversing controlfpass.

ler A is thenV moved'to'the forward or rereverser RqisV energizedthrough resistance 6l and contacts 55-53-#5e-8, but no our.-

rent ywill flow as wires 8,10 have not f.'

been connected. Y It'will be seen that the cir-` cuit ljust describedYcan lonly be lcompleted -7` l f when the interlocks on linebreakers Dand` yE are inthe positionrvshown,which corre.. fthe x open position ofthe: liner" breakers.- y l f The master controller M ismnow moved 'tospends to the Yfirst position. Thisl energizes 4'the reverser circuitjustdescribedand the reverser:V R is 'thrown to connect the/armature andfieldfwindings of the motorsM1,.M2,2for opy erationin thedesireddirection,V andy at `the-fL y y same time move the-reverserinterlockcon-1f tacts iatothe right.` VThe ourrentfwill now pass from, wire Lto--coil e, on the reverser to ithrough ythe line breakercoi'ls 62, 63,

interlockOGi-f--L-S and from ,8f to l0 through the master switch M.,Line rhbreakers E and now close, the circuit'then. being from wire 4,coil 4-41-62-63--60 (il--A'-S-lO.v Wire 2- Aalso energizedv through themaster controller AM., 'currentV passing to65'-2012-1`0,thus'olosingtlie"' l, relayV TV and allowing `current topass 'c from,VIA

2%13-10-14 throughthe Vpilot motorV ar-l mature 16-'15 pilot Vmotor`field resistance Y66, brake magnet-.winding` 62T, *contacts of .j relayT, resistance` 68440. The connections y. for operatingthe pilot motoraretherefore i complet@V andv they motorv is energized but will notrunas vthe armature isshort-circuited by the'contacts169of thev relay Sthrough the' i resistance 70, the relay S .being springbiased to? theclosed position;

and relay winding 72 to ground. this'being the Yfirst series runningposition with-all resistance 1n circuit.

r vThe maincontroller'will not advance to The closing ofthe j linebreakers completes the power circuitof i ."'mfain'controller towardsythe second notch;y

the, se'cgadf pentita @gaat :011m 'Setas-s Vthe rsistances R1, E?,.until the master'elontrollerM is-'moved tothe .se-cond positron,

seais? inf which Wire i is4 'energizjed.r` 'l This ailoivs current vtopass from l-flato the armature flvfof notching relaythencethrough '1"vrelay Stowire 10.1? fj'hovvever, the main l our jentj-i'stoo high inthecoil 72' to allow Vthe armature l0 v Y1i 'to -inalfef'contact at l, re`lay"A S1 ivillr not be energized and the pilot motorwvillnotrun.:`Yilh'en the main current Jv,relay S to 1,0. This'fvvill open contacts 69decreases to al predetermined -amount,` 'contactlis'A made [at v laandlourrent passes to l",

alloivingfthefpilot `:motor Vto advance the VVlien' `tl1e firstsegmentfof contacts Gconneot Vcontacts,Y 2a and "2", v'current rwillthen flowffromQ-QE-ZZ coils 77v and 78 to '1b and in this Waythelcirciit through relay S Will'be maintained' regardless of' the'value of the'rnaincnrrent in "thejoolil 72so that the Ymain controller"ivilladvance until +21? are disconnected. Y n

, The cutting out f of the 'first section of re stances R1, vrRwillagain increase the "main currentholdingv the armatureZl away fromkcontact la, so that the kpilot motor ,will-f be'.y again*2 stoppedlo3??they closing 'of con'- taets 69; until lsuchrv a time as the`armature 7lY isflreleased, whenfthe Y saine sequence of operations Willtake Apla'ceand i y 'ne `main cp trollerfbe advancedt'othe 4thirdposition.

y tvillbeobservedjthat throughout this, se- 'qne ce of opiterationsT1the jpil'ot motor is contmnously energized, .and consequently iorake'LAdoesnot come into operation, VThe,ina-in, 'controller Will thereforeadvance V under the"v control'nof relayf C until the sixth notclhrisreached, VWhenffcontact vl comes op?- positeljagap Uin segment H. 'Inthis position fthe motors are connected across thev line Without anyseriesresistance.

It has been Vassumed"in thev operation of cutting 'out theserliespresistan'ce lthat the accelerating current always decreases toat valuebeloiv 'that for'which the-i1otcliing re'- layrC'isset torelease.7 If, however, the

fcurrent' does inot rdrop-ai movement of the `Vmaster e(mtrollerv handleto the Jthird posi-4V l tion'f'en'e'rgizesfthe .Wire 6 and the by-passcoil 5G 'on the' notchingvrelay' C.. 'llie arma-y turey'lf) -Wfilltherebybe moved to make enl gagementWitlitlie endV ofthe armature 71 andthe contact l? vwill r*be shortv circuited through .circuitincludingthev armature 7l,

the hookhonthearmature 7,9, the armature TT-9 thearmature SOfandcontactsvl. The

relay S' is therefore energized andthe pilot 'motorvwill advanceoneinotch and thereupon be larrested from *further Y movement since theeoilsTZ-,and 'TSS ywhich are in series will be energized avt-,contacts2, 2", and the contacts 8l Vwill be thereby opened, thus deenergizingthe 'relayrSf A movementof the mastery controller barili again to thesecond .positron Will fallowy vautomati'e aecelfer-atifon to ocour,or ifthe cnr-rent will still not decrease to vthe calibrated val-neofthe'notchingf relay .C a movement 'of the master-*controller to the thirdposition Will'take another notch.'

- A movement of the master controller to c the fourth positionWillene'rgiz'e Wire '3 and this again allows-'current to pia-ss to l on"relay C, when the sequence of operation for vthe series' points VWillbe repeated until thev main controller reaches the tenth notchcorresponding tothe two main ,motors being vconnected'in parallelwithallresistance out out and With full field; If the'currentv does not dropltoits predeterminedvalue when the main controller is being rotated to thevfull;:parallel position, the pilotnotoir can beadvanced one notch bymoving the 'inaster? controller to the fifth position-'.`

This arrangement rallows theV 'driverto "control each notch' in a very*convenient manner, as hey can move the Amaster controller handle fromthe rst position to .the

third position Without dwelling on `the seoond position, and -he Willthen-take only one notch. mnst move the Ihandle back to the second.position andthen onagainto thev third nient Y v Fig. 2 shows a modifiedmaster'controller itil', which may be substituted for the con troller-M, l, Without requiring` any alterations l1n the arrangement 4orconnections of the control system. In place of the five positions shownon the controller M, the

controller M1 has only'ffou'r positions. 'The vfirst-andsecondpositionsy of controller M1 corresponds with the` vfirst and secondpositionsrespectively of the controlleriM. The third positiony ofcontroller' `M1 corresponds with' the fourth position` of controller M,

To obtain each successive notch he ivliilstoth'e fourth position ofcontroller `Ml i energizes train 'Wire 6 Yandfbrings the bypassfeaturefinto operation.'- Thus only one 'position of the controllerM'1gives the 4luy-pass'feature and th'creforefa master controller. ofy moresimple construction is provided; `A further advantage of using' cion-Atrollerli/1 is lthat iny moving from the ofl2L position` to eitherthesecond Y'or the third position they Contact segment opposite finger 6 isnot passed over andtherefore the possibility of'advancing the maincontroller one notch prem-aturelyy as might be the case with thecontroller 'M when moving from the off-position to the fourthpositionAis 'tween vthe kthird and 'fourth positions, arranged to biastheVcontroller handle towards the off-position, but only from-the vfourthto the' third position.j This spring materially Y assists thevop'er'atoras the fourtlror by-pass position 'is not reached without a'certainamount of additional force beingappliedto `*the handle., .Thus`the operatorgcan move the handle to thev third position, Ywhich isrthenormal full-on position, withouttherisk of Vtaking aby-pass/ stepaccidentally. Another advantage of employing thespring is .thatftheoperatork is less likelyfto hold the controller inthe fourth position.YVand .there-kv forethe Vby-'pas's coil which-is usually notlcontinuously rated, isv not -so liable tok be left incircuit forfanundue length 'of time.V

Another ,modified 'master controller M2 is Y shown in'Fig. '-3, whichwisVsimilar to Fig.

2i with -thev exceptionr that .the segment of finger 6v provides theby-pass Yconnection on the third position instead of on the fourthvposition. position Hof, the master controller is the In this casethejnormal lfull-on e, fourthposition and therefore to Voperate theby-pass from thefourth position the operating lever.V is returned` toythe-third positionv andeto operate theby-pass from the second 'an' orseriesposition the` operating lever isadvanced from the-second positionto n the *third 'positionj"V .l Y, Y Y A. further modifiedinastercontroller lM3 is'shoWninFiga, which differs from Eig.V

intthat the by-pass contactvhich is'V op? l posite/ lingen"V 6,-reachesVoverjtwo divisions Sitis difficult for the operator when notching up bymeans ofthe by-pass to tell when 1.oIn combination, a main controllerar-V the full series positionjhas been reached bei causezingettingtheby-pass connection'the i n fvicefor causing the step by stepV advanceofi I the main controllerto be normally under the "1i parallel contact 3is also made, whereasin Figa the notchingbetween the second and thirdlpoint will "give full series andr the parallel points Lwill not bereached until r:theV

fifth stop'on vthe controller.

l 7Vha-t we claim as new anl desire to'. secure by Letters Patent-oftheUnited States, is

' ranged tobe advanced stepbyl step forv stint-A ingiel-ectric motors,acurrent limitidevice Y'co `for causing thestep `by step advance of themain controller `tofbe normally Vunder vthe control of themotor'current,a' multi-posi# tion manually operated master controller 'for cooperatingwith Vsaid, current limit device to determine'at will the limit tofwhichsaid' main controller is automatically advanced under,` the control ofsaid device,and

means wherebyj the said controlleriscaused toy advance stepbyfstep'independently .ofV I i -1,57 6,1e7 q fthe lmotor current byfoperatingthe said mas-iff. 'terrcontrojller between positions ofthe same. l

ranged to beadvanced stepbystepfor starting electric motors acurrentlimi't device for` fi-f l vof the motor current,V amulti-position'l fi manually operated master controllerfor co1 iydetermineV at will the flimlit: to s which said lvice to determine atwill the limit to whichV "vanced under the control of` said device," "3

Vis rendered temporarily ineffective by ad.; v is desired that the maincontroller shallad.

The; arrange-v,

position cooperating with said current limitdevice 2.l In combination, amain 'controller ari causing the, step by step' advance 4of the mainl'IQy controller'to be normallyunder the control .v

operating 'with said' current limitdevce to j maincontroller isautomatically. advanced underthe control of said device, andmea-nswhereby sai-d mainy ,controller is .caused `to...` advancestepfby stepindependentlyofthe 2: motor current lby advancing the said ,master e,controller to a denite'position and return-T ing the .master controllerto a preceding `positionfj"vv y D Y ,3. In combinationVa main controllerar- 'f ranged to b-e advanced stepby stepfor start# 85,1 ingelectric'motors, a currentrlimit device .forV causing theYstepbygstepadvance of the i Y main lcontroller to benormally'under thecontrol of the'motorpcurrent, `a multi-positionv manually operatedmaster-controller Y for cooperating with saidl current llimitrdesaidmain controller `Vis automatically ad.-

means whereby the saidcurrent limit device vancing the-'said mastercontroller'to. 4a posif tion in advance ofthe ,positiontox which itvance, and connectionsV whereby the master controller must Ythen bereturned to aposi. tion correspondingto the position'to which themaincontroller has' advanced'before thai maincontroller can .advance tova furthere 'f n under thecontrol of the master con-.- *1- Q.

troller.f v i .-H 4; In combination, a main controller for i `startingelectricmotors, a current limit'def-.sfi` 1 control ofjthemotor current,a multi-posi tion manually operated master controller for to determineat will the limit to which said main control-ler isA automaticallyadvanced', 1 under the control ofsaiddevice, meansgunc .der the` controlvolf-*said 'controller'l for perf vmittingfsaid mainfcontrollertoadvance a V Q step independently of the motor current, and @1' ifconnections whereby Vthe said main controlfl 129 ler is preventedV fromtaking a further ad'f V VVance step until after the said mastercontroller has been-returned to a preceding posi j i tion. In witnesswhereof, rwe have hereunto set 1.25 c our hands this 22nd day ofSeptember 19274. j

HAMMOND. C, HASTINGS e vEDWARD Bi V'IUPPEl\l.V

